UK The core difference
ATEX is a legal requirement in the European Union: equipment for explosive atmospheres must meet directive 2014/34/EU before it can be placed on the EU market. IECEx is a voluntary international certification scheme operated under the International Electrotechnical Commission. It certifies equipment to the IEC 60079 and ISO 80079 standards and is accepted, or adopted directly, by many countries outside Europe.
The technical content is very close. ATEX relies on the European versions of the same standards, published as EN IEC 60079, so a product that passes one set of tests usually has most of the evidence for the other. The differences are legal and administrative: who must certify, what paperwork results and where it is recognised. Our ATEX explainer covers the directives themselves.
What IECEx is
IECEx, the IEC System for Certification to Standards Relating to Equipment for Use in Explosive Atmospheres, is run by member countries through approved certification bodies (ExCBs) and test laboratories (ExTLs). For equipment, the scheme produces three linked documents.
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Certificate of Conformity (CoC). States that the product meets the listed IEC standards. Every IECEx CoC is published on the scheme’s online database, so anyone can check it.
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Ex Test Report (ExTR). The detailed test evidence. Other certification bodies, including ATEX notified bodies, can often reuse it instead of repeating tests.
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Quality Assessment Report (QAR). The audit of the manufacturer’s factory, repeated at intervals, which IECEx requires for every certified product.
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Wider schemes. IECEx also certifies repair and overhaul facilities and the competence of people who work on Ex equipment, which the ATEX directive does not.
IECEx and ATEX compared
| Aspect | ATEX | IECEx |
|---|---|---|
| Legal status | Mandatory EU law | Voluntary scheme; some countries adopt it in law |
| Where it applies | European Union and EEA, with CE marking | International, including Australia, New Zealand and many offshore and Middle East projects |
| Standards | EN IEC 60079 harmonised standards | IEC 60079 and ISO 80079 |
| Zone 2 or 22 equipment | Manufacturer self-declaration allowed | Always certified by an ExCB |
| Who certifies | EU notified bodies | IECEx certification bodies (ExCBs) |
| Main document | EU-type examination certificate and EU declaration of conformity | Certificate of Conformity, published online |
| Factory audit | Required for categories 1 and 2 | Required for all certified equipment |
| Marking | CE, Ex hexagon, group and category, then the Ex string | The Ex string and IECEx certificate number |
| People and services | Not covered by the directive | Repair facility and personnel competence schemes |
The practical upshot is that IECEx is stricter on process for low-hazard equipment, while ATEX is the one with legal force in Europe.
Markings side by side
Because both schemes use the same standards, the core of the marking is the same. A Zone 2 device certified to both might carry the ATEX marking II 3G Ex ic IIC T4 Gc and the IECEx marking Ex ic IIC T4 Gc, each followed by its own certificate number. ATEX adds the CE mark, the Ex hexagon and the group and category (II 3G); IECEx relies on the equipment protection level (Gc) to show the zone.
Certificate numbers look different too. An IECEx number takes the form IECEx, the certification body’s code, a year and a serial, such as IECEx BAS 12.0045X, while an ATEX number ends in ATEX and a serial. The X suffix means the same in both: specific conditions of use apply. Checking an IECEx certificate is quick, because searching the number in the public IECEx database shows its scope, the standard editions used and any conditions; for ATEX you need the certificate or declaration from the manufacturer.
The 10.1 inch ATEX Zone 2 model in our rugged tablets range is an example: its manufacturer lists both II 3G Ex ic IIC T4 Gc under ATEX and Ex ic IIC T4 Gc under IECEx, plus a Class I, Division 2 listing.
Which one does your project need?
The site, not the product, decides. For a manufacturer the choice is mostly cost and reach: an IECEx test report is accepted by many certification bodies worldwide, so one round of testing can feed ATEX, UKEX and several national schemes. For a buyer, the question is simply what the site’s rules and the operator’s own standards ask for.
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A site in the EU. ATEX is mandatory. IECEx is optional but useful if the same design is also going elsewhere.
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A site in Great Britain. CE-marked ATEX equipment or the UKCA equivalent; IECEx alone is not enough.
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Australia, New Zealand and many international projects. IECEx certificates are accepted directly or form the basis of local approval, and oil and gas operators often specify them.
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Multinational fleets. Equipment with both ATEX and IECEx, plus a North American listing where needed, lets one design serve every site.
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Installation and maintenance. Neither certificate covers how the kit is installed. Work to IEC 60079-14 and inspect to IEC 60079-17, with competent people.
Quick answers on IECEx vs ATEX
IECEx and ATEX: common questions
Is IECEx accepted in the EU?
Not on its own. Equipment sold in the EU needs ATEX, though an IECEx test report can shorten the ATEX assessment.
Is IECEx mandatory?
Only where a country adopts it. IECEx is voluntary, but some countries and many operators require it for hazardous area equipment.
Is ATEX stricter than IECEx?
Not technically. Both use the same standards. IECEx is stricter on process, because it certifies Zone 2 equipment that ATEX lets manufacturers self-declare.
Does IECEx cover dust as well as gas?
Yes. IECEx certifies equipment for gas and dust atmospheres, using the same Ex marking with Da, Db or Dc protection levels for dust.
Can one product have both ATEX and IECEx?
Yes, and many do. Manufacturers often certify once to IECEx and reuse the test report for ATEX.
Our hazardous area panel PCs include models with both ATEX and IECEx Zone 2 marking, and our work in oil and gas means we are used to matching certificates to international sites. We integrate and validate each system as standard, within its certified configuration.